Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
te sach » toc sach
lua tre » cua tre, dua tren, luat tri
danh vi » hanh vi, dinh vi, danh di
va danh » va dinh, va dan, va hanh
sach ky » sac ky, sach y, sach ty
nam xua » nam cua, nam mua, nam qua
luy tre » luyen tre
xua va » xuat va, vua va, sua va
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky nang ((x hoi) OR (o hoi)). hieu quang nam xua va danh vi ((lua tre) or (luy tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang ((x hoi) OR (o hoi)). hieu quang nam xua va danh vi ((lua tre) OR (luy tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang ((x hoi) OR (o hoi)). hieu quang nam xua va danh vi ((lua tre) or (luy tre))".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ((x hoi) OR (o hoi)). hieu quang nam xua va danh vi ((lua tre) or (luy tre))*.